Flotation apparatus



wz?. tm June 7" 11M. OWEN ETALd 'FLQTATION APPARATUS Filed May 29, 1925 s snewsheet 1 @gli/mg@ me 7,19% 2,633,382 I T. M. OWEN ET AL FLoTATroN APPARATUS Filed May 29, 1925 s sheets-sheet 2 fdwdohz T0772/ Z. 020679.

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0: sind June 7 9 1927.

T. M. owl-:N ET AL,

FIJOTATION APPARATUS Filed May 29.V 1925 3 Shams-Sheet 3 Patented .lune 7, 1927.

TOM M. OWEN, F WALLACE, AND MOHAELP. DLTON, OF MULLAN, IDAHO.

FLOTATION APPARATUS.

Application mea my 2a, 1925. serial No. 33,601.

Our invention is an improved apparatus for the flotation `concentration ot ores, but has utility for' other processes wherein it is necessar to agitate or serate, or both 5 agitate an aerate a body ot liquid er of mixed vliquid and solids. ln the practice of the flotation process by the mechanical agitation method, it is generally, in fact almost invariably, desirable to subject the ore pulp 1U to agitation in a considerable number ot sepa *ate agitation cells. This involves thc necessity ot providing some means of conveying the pulp from cell to cell and maintaining it at the proper level in each cell.

llVhere the conformation ot the land admits it is often convenient to ett'ect this purpose by placing the cells successivclyat a lower level and initially supplying the pulp to the uppermost cell. t frequently happens, however, that it is necessary or advantageous to build all of the cells upon the saine level.

' In a prior application led by us (Serial No. 724,250, filed July 5, 1924), we disclosed a flotation apparatus of the typelin which the cells were erected on the saine level, with the agitator rotors mounted ona single shaft extending throughout a series of cells.

Bearings Were provided at intervals alongA the shaft, preferably between the cells and Within bearing spaces from which the pulp is excluded. Associated with cach of the cells (except the first in the series) was disclosed an elevator chamber, in which was a rotary elevator mounted on the same shalt 'as the agitator rotors. These elevator .chambers were connected with the cells on either side in such a. way that the pulp flowed from one cell into thc chamber at a low level, and thence lifted to a high level s0 as to impart the necessary lion' bv gravity 'into the next cell. In this way the pulp flow was maintained throughout the series of cells o n the salue level.

rl`he present invention involves the sainel principle of operation, but dill'crs in its application, in that the elevator chambers are eliminated and vone end portion of each agitator rotor utilized as the elevator, this being readily accomplished by making certain 5" changes .in the' structure of the cells. The

results arequite the same, but with the advantagev that the cells are of a simpler con- Figure 5 is a transverse scctiontaken 0n.

line 5-5 of Figure 2; and

Figure (i is a detail vien' in longitudinal section on ln'c (3-13 oi' Figure As illustrated in Figure l, the pulp is initially delivered by any Isuitable means to the cell 1. shown at thc right., this being the head ol tlumachine. As shown herein the t.lnee.rc.lls l, 2. and il are similar vexcept in the lzul that cell 1 is liot.[n1 \il l tvih any elevator nufcluinisin, the pulp being initially delivered to that cell from some outside source. In the l'orm shown each cell is divided into-two compartments by means of a central partition 4. 'ln practice, the number ot' partitions may vary or be entirelydispensed with, but. in most instances one or more such partitions are advantageous in order to get better control ot' the differing grades otl concentrates.

lVithin each cell is a cylindric agitator rotor 5, mounted on a main shaft extending lengthwise through the cells, and jour nallcd in bearings at r(and 8, located at the head end of the machine; at 9 and 10, between the cells 1 and 2, and 2 and 3 respectively; and at l1, the tail end of the machine. rl`his shaft may be operated from any suitable source ol power as through a bell' applied to the pulley l2. y

llarh cell. is of substantially rectangular.

form and comprises a vertical bark tvull lil, and vertical end walls 14 and 15, As indicated in Figure 5, the front wall 16, op posite theI agitator rotor extends upwardly to a point somewhat below the level` of the axis oi thel shaft and there carries an in'- clined apron 17 provided at its upper edge with a vertical lip 18 over which the concentrate t'roth flows into the launder 19. The height of front wall 16, the presence,

' struction, shorterin length and less costly f'or absence, and the size of members 17 and to install and maintain.

The features embodying theinvention will 18 are preferably controllable at will to suit the requirements rot the pulp under treatnient. The space immediately below thev members 1T and 18 and forwardly of the agitator chamber torni what is termed :spitz- '(see Fig. 5) is a hood 23, at the front of which ia a depending vertical wall 2l, which terminates below the level of the shaft. 6,

' and of the overflow lip 18. A vertical balle E has' its upper edge extended between the depending wall 2l and the periphery of the agitator lrotor; The agitator rotor revolves in a counter-clockwise direction as indicated by the arrows, antlithrows the pulp, 'iiward and for 'and aS indicated by the arrow;` 30, and at the front of the cell the pulp passen through tlie slot 2G between the walls 24e and 25 `into the spitz-box H as indicated byl the arrow at that point. The lower` edge of the baille 525 is spaced above the floor of the cell to forni an opening or slot 2i'. An inclined floor "2S preferably extends from the front wall 1.6 to the horizontal floor ot the cell to a: t in directing the tlow of pulp through the alot 2 in the direction indicated by the arrow placed at that point.

T he baille Qfr in connection with the front.`

Wall 1G and floor board QS, forms a spitzlbox at the front of the cell, the overflow of froth over the lip i8 being received in the leander 19 and discharged through the duct 29.

' It will be noted that in the preceding description no mention is made ot' an elevator chamber or an elevator. ln fact, no such parts exist ae separate elements of the apparatus, but their function is perforn'ied by a section of each agitator rotor, at the head end of each cell. and by the adjacent portion of the cell. Thus, aS shown in Figures 2 and the portion at the 'right end of the cell is lthe elevator section thereof. linmedi'ately in fifi-ont of the endof the rotor is an inlet chamber BO, between the end wall la and head end oi? the spitz-box l, being separated therefrom by a transverse partition wall 3l (Figure ai). The rear wall of the chamber is 'formed by the Same vertical walls Z4 and extending' throughout the full length ot the cell, :.ilthough the slot between their overlapping edgesv is closed by a block 32, inc-lined downwardly from the end wall l-l beyond the partition wall 3l. and projecting` into the slot .26 to the spitzbox K to the left. 'The lpurpose of this block 32 will be presently pointed out. The front of the chamber 30 is formed by a ver- @senese ot' the end wallie of the afeociated cell,

and thence beyond to the end wall l5 ofthe adjacent or preceding cell. llearwardly the front. wall 33, is a vertical wall 3%, ei;- tending crcaawise between the end walls lli and l5 and forming.; an intermediate chainber betweeirthe. preceding cell and the .inlet chamber tl, Said intermediate chamber being just forward ot the lahaft bearing),` 9 and the space between the cells occupied thereby. Aa clearly shown in Figure l. the inlet chamber 3() is about one halt.' thc height oi the cell and is closed by a rcmmable lid 3G, havingl one central openincr 3o". Moreover, the inlet chamber conununicutcs at its bott-om with the cell proper. or agitator compartment. by an openingA or slot .'T, the aannbeing a continuation of the alot JT on the other aide of-the partition wall ill.

As clearly shown in Figure l. au opening 3S lornicd in thc tail end wall 14') oi" the lireceding cell, and near the bottom thereof. said opcning or passage communicatiner with thc intermediatechamber 35. In the opposite wall ll, the :amc being the head end wall of thc cell to which the pulp tlowine'. is an opening lit) -from the intermediate chamber 35 into the inlet chamber. lhhl opening' titl, is located at a higher level than the inlet opening IS to the chamber 555; ite lower edge determining the pulp level in the precedingcell. ln other words, wall 4U. bclow the openingl 39. acta as a wcir over which the' pulp flows into the inlet chamber 250. For thisV reason the wall 40 ia preferably made insectional. forni, as shown, so that thev level may be altered in order to change thepulp level in the preceding cell, as re-.

quired. f

The saine arrangement is duplicated in the next cell beyond, and regardlcas of the number lof cells in the series, all between the head and tail cells are of the same construetion. l

Assuming then that the pulp is introduced into the cell 't. at the head ot the series, it is agitated therein by the rotation or" the agitator rotor, and what mineral laden froth is Jformed overllowa` the Spitzbox into the laundcr i9. The pulp on reaching the tail end of the spit/box of head cell l, passes vthrouch the openiircr :b into the intermediate chamber B5. the level of pulp therein. as well as the cell l. being governed by thc height-ot the weir it). as already described. .is the pulp overllowa` the Weir into the iiilct' chamber 53u. it passes. through the. opening' 23T into lthe bottoni of the agitator compartment ol' cell :2g where it is picked up by thc cnil portion ot' the rotor and carried upwardly around. the,`

same in a path indicated by the arrows in,"

Figure 3, the general movement of 1 io pulp lin) llt)

paratus,

' a vertical p tail, there is little or no retardation ol they incoming pulp. ln `other words, it is not necessary that a distinct elevator chamber he' formed, providing the pulp is not thrown back into the yinlet charnher, which,-oi course would cause recirculation and retard the action. closing ofi the inlet chamber 36 atlthetop, by the block 32, which detlects the pu p laterally into the mass ofthe pulp, beyond the zone of the entering pulp, l

l desired, the longitudinal strips 2l may stop at the end elevator section and e dlier ent type ot elevating' elements be 'substituted, although this is a mat-ter of choice since the strips 21 will. serve equally Well to pick up the pulp and carry it upwardly and discharge it at a higher level than that atwhich it entered, which is equivalent to` saying that it discharges the pulp at a higher level than the pulp level in the preceding cell.

As is customary in. apparatus of this type, air is admitted to the cells, preferably through an opening in one of the end Walls, surrounding the rotor shaft. The air thus admitted or drawn into the cell is mixed with the pui. in the agitating' process within the cell. he pulp thus undergoing treatment is being continually discharged into the spitz-box K, through the space or slot 26, the froth rising to the top where it overows into the launder 19, wheeas the heavier mass is returned to the agitator compartment through the opening 27, at the bottom of the spitz-boxln the practical yoperation of flotation ap it has been found that where an excess f air is admitted to the cells, large hublolesl are formed in the pulp froth which rise to the top of the spitz-loon and give way, thus creating a more or less disturbed In orderl to eliminate this condition and to maintain a froth of a line bubble texture and thus to promote a condition of quiescence .in the froth layer, We have devised a sunple and effective expedient for 4bringing about this result. r

Referring to F1gures 5 and 6, we mount late 42 tothe outer face of the upper section 24 of the iront wall of the This, however, is avoided by' cell, with a space of 1/8 to Q inch between. The lower ed e of the plate extends below the bottom e ge of the wall, a distance of from l to 2 inches, so that the froth passes underneath the lower edge of the plate be fore passing upwardly into the froth layer at the top of the spitz-hox.

The plate 42 l is spaced from the wall 24 by suitable strips 43 .o wood arranged vertically spaced apart at intervals. As the froth enters the spitzhon through the opening 26, the large 5 huhhlesrise to theltop and are trapped behind the lower edge of the plate 42, whereas the small and uniformly tine bubbles pass beneath the plate and enter the froth layer .,:z

at the top of the spitz-hou. The larger bubbles thus trapped by the plate are forced upwardly in the vertical passage formed bythe plate 42, and as they break the air is released and escapes from the top to the atmosphere., It is preferred, however, to provide a chamber .44 along the top of the plate 42 witlra pipe 45 connected with' one fend thereof, its other end communicetingwith the interior of the cell,`

through a'nbintalre inlet opening, preferably associated' with 4the air inlet opemn s to the celllocated around the shaft 6, at t e point where it' passes through the side wall of the cell, Thus the air entering the 'chamber 44 from below is returned yto the cell, the reason being that the air is usually charged with a certain amount of the pulp treating reagents and thus by using the air over again, these reavents yare recovered and utilized.

We claim as our invention: p

1. A lflotation` apparatus comprising a series of cells, an agitatorrotor extending horizontally ofeach cell, an inlet vchamher communicating with' each cell adjacent the bottom thereof through a discharge openin directed toward a relatively short longitudinal portion of said rotor and connected with the precedin cell through an inlet opening at a substantially higher level than said discharge opening, said portion of the rotor acting to elevate the pulp to a predetermined level 1n each cell. v

2. A flotation apparatus comprising a series of cells, an agitator rotor extending lengthwise of each cell, intermediate chambers connecting the tail end of each cell with the head end oit the following cell, through a discharge slot adjacent the bottom thereof and directed toward a longitudinal portion of said rotor less than the full length thereof, said portion of each agitator rotor acting to elevate the incoming pulp to a predetermined level in each cell above the discharge opening thereto.

3. A flot-ation apparatus comprising an aligned series of cells, an agitator rotor in leach cell, a duct connecting Vthe head end of each cell with each precedmg cell, below the pulp level in said preceding cell through a laoI I level therein.

longitudinally the length ot each cell, a

chamber connecting each cell With the preceding cell through an inlet slot adjacent the bottom of said cell and below the level of the discharge from said preceding Cell, said vslot beinggdireeted toivard a section ot said. rotor at the head end of Said cell, whereby said end section acts lto elevate the pulp entering said cell and to maintain a predeternined pulp 5. A flotation apparatus comprising a cell, a rotary agitator extending lengthwise of said eell, an inletehamber communicating with said cell through a longitudinally extending opening below the pulp level in said cell and directed toward a relatively short end of said agitator at the head end of said cell, and a spitz-box extending throughout the remaining portion of' the length ot said agitator, said end portion thereof acting to elevate the pulp entering said cell through said opening to the uorinal pulp level therein.

(i. A flotation apparatus comprising a celh a rotary` agitator extending lengthwise of said Cell, a spitz-box communicating with said cell and extending substantially throughout the length thereot, an inlet Chamber` formed at one end of said spitz-box A,and

conununieating with said cell through an.

the agitating and discharging section there-- 7. A flotation apparatus comprising an agitator chamber, a spitz-looX separatediromsaid agitator chamber hyvertieal partition Walls forming a passage connecting said chamber with said spitz-hex below the trotli level therein, a Wall spaced outwardly from said partition wall and extending into-said spitzox below the froth level therein and.

terminating substantially opposite the pas-y sage from said agitator chamber and said spitz-bomto form av vertiealpassage for the escape of air for the purpose described.

8.A flotation apparatus comprising an agitator chamber, a spitz-loox separated from .said agitator chamber by vertical partition Walls forming a passage connecting said ehainber with said spitz-box below the froth level therein, a Wall-.spaced from said partition Wall and forming therebetween ayertical air passage opening downwardly into said spitz-lool(` adjacent said opening, a chamber' communicating With said air passage at its upper' end, and a passage connecting said chamber with said agitator chamber,

Signed at lVallace, idaho, this 21st dey et May, 1925.

' TOM M. erven.

MICHAEL r. Damon. 

